The spec freeze that is due in two weeks will freeze the list of features that might get included in the release. These features then need to be implemented before the code is frozen at April 30, otherwise the feature will be excluded from the release. After that, another month is spent on stabilizing the release, eventually resulting in the preview2 release. The following release candidate will be delayed "as long as any bug tickets remain". If everything goes well, that is, if no new bug reports appear after 1.9.2-p0, the final release should be due in mid-August.